Centrifugal casting-machine.



Patented June 15, 1915.

10 ,M' wenfi fei'i'irelf P. 1. PANKRATZ: CENTRIFUGAL CASTING MACHINE. vAPPLICATION FILED MAR 5 1914 I I'ETER J. PANKTtATZ, 0F STAFFORD, KANSAS.

GENTRIFUGAL CASTING-MAC HINE.

Specification of Letters Patent.

Patented June 15, 1915.

Application filed March 5, 1914. Serial No. 822,617.

To all whom it may concern:

Be it known that 1, PETER J. PANKRA'rz, a citizen of the United States,residing in Stafford, in the county of Stafford and State of Kansas,have invented new and useful Improvements in CentrifugalCasting-Machines, of'which the following is a specification.

This invention relates to centrifugal casting machines and has for itsprincipal object the production of a simple and efiicient device adaptedmore particularly for casting dental inlay fillings and other arm ticlesor pieces of irregular shape.

Other objects and advantages to be vattained will hereinafter more fullyappear.

The invention consists in the parts and in the arrangements andcombinations of parts hereinafter described and claimed.

In the accompanying drawing illustrating an embodiment of the inventionin a dental casting machine, and wherein like symbols refer to likeparts wherever they occur in the several views, Figure 1 is a plan viewwith portions of the casing-removed to expose in vertical section. Fig.3 is a horizontal section on an enlarged scale on the line 3-3 of Fig.2; Fig. 4 is af-ragmentary vertical section on the line 4.-4= o f Fig.3; and Fig. 5 is a view of the parts shown in Fig. 4, showing the mannerin which the latch pin on' the rotatable column member engages therecess in the motor sleeve. 4

The machine illustrated in thedrawing comprises a circular supportingbase 1 at the center of which is a post or spindle 2.

At the top of the base 1 is an annular flange 3 which constitutes ahousing for a motor spring 4; Thisspring, as shown, is an ordinaryspiral or clock spring, one end of which is fastened to the flange 3, asat 5, the fastening means being a bolt which is passed throughperforations provided therefor in the motor spring; Fig. 2- is a viewpartly in side elevation and partly' flange 16 is ment 22.

motor sleeve,

provided with a central. opening thr ugh, which the motor sleeve 6projects, said sleeve 1 having an annular flange 10 overlying theadjacent portion of the cover plate.

Sleeved over the post 2 so as to rotate thereon is a tubular columnmember 11.

This column member is closed at its upper end and is provided with acounterpart socket or" seat 12 which receives the rounded end portion 13of said post 2, and which constitutes a journal bearing. The post 2 isprovided near its upper end with-an annular groove 14, and a pin 15 isinserted transversely through the column 11 and tangentially throughsaid groove 14, so that the tube is free to rotate on the post 2, but isheld against endwise movement thereon.

The lower end of the tubular column 11 just clears the top of the motorsleeve 6, and it is provided with an annular flange 16 which is oflarger diameter than the flange 1001? said sleeve 6. The flange 16 isprovided with a peripheral notch 17 adapted to be engaged by a lateralprojection 18 on a latch member or pawl 19, which latter is pressedagainst said flange 16 by a spring handle extension 21 whereby it may be5 moved and held out of engagement with said flange 16.

Diametrically opposite the notch 17 the l provided with a boss orenlarge- This portion of the flange is provided with a verticalopening'through which works a latch pin 23, a spring 23 being providedto move said pin downward and yieldingly hold it in engagement with theflange port1on'10 of said motor sleeve 6.

The lower end portion of the pin 23 is beveled, as at 24:, and theflange 10 of the motor sleeve 6 is provided with a correspondinglybeveled recess 25, at one end of which is a shoulder 26 against whichthe pin 23 engages when the column 11 is rotated in one direction,whereby this motion is imparted to said sleeve 6, and whereby, also,when said sleeve 6 is rotated in the opposite direction its motion isimparted to said column 11; By this arrangement it is obvious the column11 the latch pin 23 will ride out of the recess 25, whereby said sleeve6 may remain idle and the member 11 is free to. rotate independentlythereof. Near the upper end of .the column 11 it is provided withoppositely disposed radial arms 27, 28. On the arm 27 is fastened,either fixedly that on the reverse rotation of I or removably a crucibleor container 29. This crucible, as shown, is tubular and it is providedwith a horizontally elongated slot or mouth 30 in its side. The crucibleis open at its inner end, but it is provided with an upstanding flange31 at the bottom there of. The outer end portion of the crucible isconvergent or frusto-conical, as at 32, and is provided with an annularflange 33 whose outer face is preferably beveled or tapered. Thecrucible is lined throughout with asbestos or some suitable refractorymaterial.

The outer portion of the arm 27 is inclined downwardly, as at 34, and ithas slidably mounted thereon a flask-holding device 35. As shown, thisdevice comprises a plate which is mounted on a block 36 having anopening therethrough which is slidably fitted to said downwardlyinclined portion 34 of the arm 27. The flask, 37 is detachably supportedbetween the flange 33 of the crucible and the plate 35; and said platemay be held in its cooperative position by a spring 38 which isconnected at one end to a stud 39 on the under side of the arm 27 and atits opposite end to the block 36. In some cases the tension of thespring 38 alone may i be depended upon to hold the flask in position,butit is preferable to provide a locking device for the block 36. Asshown, the block is provided with a set-screw 40 which engages the arm27. i

The flanged end portion 33 of the crucible is set at an inclinationcorresponding rectangularly to the inclination of the portion 34 of thearm 27, and the relative position of the flask-holding plate 35 thereto.The principal object in thus inclining the parts is to support the moldso that, in forming castings of irregular shape, such, for example, asdental inlay fillings, no cavity 'in the mold will be in a horizontalplane higher than the sprue and level of the surplus molten metal, orother fluent substance of which the casting ismade, whereby the force ofgravity assists rather than retards the centrifugal force in fillingeach and every cavity and the formation of a well-defined counterpartcontour for the finished casting is secured. It is also preferable toset the crucible at an angle to the arm 27 in a horizontal plane so thatthe crucible is disposed tangentially instead of directly radial withrespect to the axis of the machine. This is to facilitate the dischargeof the molten or fluent substance from the crucible. A weight 41 issildably mounted on the arm 28 so that it may be adjusted toward andaway from the axis of the machine to counterbalance the weight of thecrucible and mold. This weight may be locked in adjusted position by anysuitable means.

As shown, it is provided with a set-screw t5 42 which engages thearm 28.

In the operationof the machine the arms 27, 28, are turned in adirection the reverse to that indicated by the arrows in Fig. 1, and thetubular column member 11 being fixed with respect to said arms isrotated therewith. The latch pin 23 engages the shoulder 26 of therecess 25 in the motor sleeve 6 and the latter is thereby rotated towind the spring 4. When the spring is wound the spring-pressed latchmember 19 is allowed to engage the peripheral recess 17 in the flangedportion 16 of said tubular member 11, as shown more clearly in Fig. 1.The flask with the prepared mold therein is then placed in positlon, asshown in Figs. 1 and 2. The material of which the casting is made isnext placed in the crucible or container 29, and in case metal is usedthe flame from a blow pipe or torch is applied thereto through theopening 30 in the side of the crucible until the metalhas become molten.The latch member 19 is then released from the notch 17 in said flangeportion 16 of the rotatable colunm 11, and the .rotatable elements arethereupon instantly whirled rapidly by the reaction of the spring '4.The column member 11 with the arms 27 and 28 thereon will continue torotate by momentum after the force of the spring is spent, as the pin 23rides out of the recess 25 owing to the beveled arrangement of the endof the pin and the bottom of said recess. The molten or fluent mass inthe crucible or container 29 is thrown into the mold by centrifugalforce due to the rapid rotation of the parts; and it has been found inpractice that the mold becomes filled quickly during the first few turnsof the device, the continued rotation compacting the material in themold while it is cooling and hardening, thereby avoiding distortion ofthe object molded, as sometimes occurs by shrinkage during the ordinarymethod of gravity molding.

The mold of itself and the manner of its preparation forms no part ofthe present invention. It-may behere stated, however, that for practicalpurposes, the mold material 43, or investment compound, as 1t is termedin dental practice, should be sufficiently porous to permit the forcingout of the contained air in the cavity by the incoming casting material.The mold cavity 44 may he of any desirable contour and the sprue 45 mayor may not be contracted, as desired, but if contracted it is preferablyprovided with an outwardly flared or enlarged mouth 46, as shown.

While the invention is shown in the drawing as embodied in a dentalcasting machine, obviously it may be employed in other arts, and themachine admits of considerable modification, not only in constructionand arrangement but also in sized proportion, without departing from thesplrit of the invention. Therefore, I do not wish to be limited to theexact constructionand arrangement shown, nor to the application of theinvention in any particular art.

I claim:

1. In a centrifugal casting machine, a carrier rotatable in a horizontalplane, a con tainer on said carrier for a fluent casting material, saidcontainer extending to one side of the axis of said carrier and havingan open outward outlet, and means on said- 3. In a centrifugal castingmachine, a ver- 4 tical rotatory column, a motor for rotating saidcolumn, a lateral arm on said column, a container on said arm for a.fluent casting material, sald contamer having an open outward outlet,means on said arm for supporting a mold in cooperative relation to, andat a downward inclination from, said container, and means forcounterbalanci-ng said arm with the parts mounted thereon.

4:. In a centrifugal casting machine, a

supporting base, an upstanding 'spindle thereon, a motor sleeverotatable on said spindle, a spring for rotating said sleeve, a tubularcolumn rotatable on said spindle above said motor sleeve, ratchet meansforengaging said sleeve and column member so that the one may be drivenby the other in one direction, a releasable device for holda ing saidcolumn member from rotation, a

lateral arm on said column member, a tubular crucible disposedlengthwise on said arm and having a longitudinal opening in its forwardside with respect to the direction of-rotation and a discharge openingin its outer end, and means on said arm for detachably supporting a moldin coiiperative relation to the outer end of said crucible.

. 5. In a centrifugal casting machine, a carrier rotatable in ahorizontal plane, a tangentiallydisposed tubular crucible mounted onsaid carrier to one side of the axis thereofand having a longitudinalopening in its forward side with respect to the direction of rotationand a discharge opening at its outer end, and means-on said carrier fordetachably supporting a mold in cooperative relation to the outer end ofsaid crucible. y I

6. In a centrifugal casting machine, a carrier rotatable in a horizontalplane, a tangentially-disposed tubular crucible mounted on said carrierto one side of the axis thereof and having a discharge opening at itsouter end, and means on said carrier for detachably supporting a mold incooperative relation to, and at a downward inclination from, the outerend ofsaid crucible.

7. In a centrifugal casting machine, a carrier rotatable in a horizontalplane',-a tangentially-disposed tubular crucible mounted on said carrierto one side of the axis thereof and having a discharge opening at itsouter end, and means on said carrier for detachably supporting a moldwith its sprue in coiiperative relation to the dlscharge opening of saidcrucible and with its cavity in a zone below the sprue.

8. In a centrifugal castmg-machine, a rotatable carrier, a crucible onsaid carrier to. one side of the axis thereof, said crucible having anopen outlet outward from the axis of said carrier and a tapered end facesurrounding said-outlet, and means on said carrier for supporting anopen ended mold flask endwiseagainst said tapered end face of thecrucible. y

In testimony whereof, I have hereunto set my hand in presence of twosubscribing witnesses.

PETER J. PANKRATZ. Witnesses:

V. B. New, ARA JALLY.

